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The Volcano That Stopped The World -

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Live. Good evening, Tony

Jones with a 'Lateline' news

update. The Foreign Minister

has been in Jakarta pushing

the case for a refugee

processing centre in East

Timor but despite Stephen

Smith's best its efforts the

Indonesians are not

convinced. They say while the

idea has potential there

needs to be more

consultation. Stephen Smith

says negotiations with East

Timor will continue over the

next few days. An audit

released by Melbourne Storm

owner News Limited has found

the club breached the NRL

salary cap by more than $3

million since 2006. News

Limited has sacked four of

the club's independent

directors and the Storm could

be forced to lose some of its

star players. In her first economic speech as Prime

Minister Julia Gillard has

sought to showcase her

Government's fiscal

responsibility and promised a

lean, green election campaign

de vowed of big-spending promises but when asked if

she reneged on a Kirribilli

move with Kevin Rudd she

refused to discuss talks.

With the Copenhagen climate

talks having such an effect

on the career of Kevin Rudd I

will be joined later with

Ivor Gabor. Join me for

'Lateline' at 10.20.

NARRATOR: 'In April 2010, an eruption from a volcano in Iceland paralysed air travel across Europe. drifted over the continent, As a cloud of volcanic ash no-fly zone ever known. it created the biggest But in the chaos, to the heart of the eruption zone.' one British geologist made it It's absolutely astonishing. to be here. It really is just an amazing sight 'Professor Nick Petford went behind the crisis. to explore the science A unique combination of geology... ..and engineering. What makes Iceland so explosive? such a threat to aircraft? Why is volcanic ash might the next eruption bring? And what disaster It's April 14, 2010. in south-east Iceland The Eyjafjallajokull volcano high into the atmosphere. begins pumping volcanic ash over Europe grinds to a halt. Within three days, air traffic thousands of travellers stranded, With airports closed and hundreds of is in disarray. air travel around the world

is completely free of ash Strangely, Icelandic airspace the eruption began, and five days after British geologist Nick Petford from the United States. has managed to fly to Iceland small volcano can generate enough ash He wants to see for himself how this over a whole continent.' to cause travel chaos got near perfect weather conditions So the clouds have lifted and we've up close to this thing. and I just can't wait to get the main eruption crater 'They're flying to to land there. to see if it's possible from the south Icelandic coast, Eyjafjallajokull rises straight up Reykjavik.' about 100 miles from the capital, into Eyjafjallajokull So we're now making our approach I can see that the plume is there. and, you know, in front of me There's fresh explosions. big lumps of material I can just about make out being flung up into the air. These are volcanic bombs, where the lava erupts and a big bomb and cools rapidly in the air and it flings out hot magma to the earth and freezes and then descends back down as a sort of lump or a... volcanic bombs. Sometimes Joe would just call them take a closer look - So we're gonna fly up there, pretty dangerous, pretty active - as close as we can, cos it's still and see what we can make out the eruption's been developing in terms of how in the last few hours. which is typical So one of the things about these kinds of eruptions comes out in waves, is that the plume an explosion of the magma and every time you can see that builds up in the cloud. you get this kind of pressure wave is distinctive. The colour of the material That was just spectacular! We had a huge burst. the magma moving in slow motion. It was almost like watching These great big dollops... in slow motion. And clearly it's not moving velocity, some of these gas clouds. It's travelling at a near supersonic amazing sight, It's just an absolutely of all the travel misery to think that this is the source over the last five or six days. that's been plaguing the world on the ground 'The pilot won't keep the helicopter this close to the crater just five minutes and he's given the crew to film and observe the eruption.' quite incredible. The sounds are really It's something of an experience to the erupting volcano. to be this close as I said before. So the two colours in the clouds, You have the dark material, fragmented into tiny particles which is where the magma's being as a buoyant plume which get carried up thermally up into the atmosphere. big cloud of steam, of white gas - And the whiter material - the that's water vapour. beneath the volcano So it tell us still because of the heat of the magma. there's ice and snow that's melting RUMBLING see this amazing billowing material. Just looking into the cloud, you can Look at the red-hot lava - at 1,000 degrees Centigrade plus. these lumps of stuff coming out just rips itself apart, There's a lot of it shooting up into the cloud. and the compression wave's It's absolutely astonishing. to be here. It really is just an amazing sight It's picking up. They're bigger. There's more and more eruption. being thrown into the air. There's more spatter There's one just gone behind me now. So I'm a bit... the helicopter's here I'm quite worried - to get the hell out of here. and I think it's time in the first place? 'But why did this volcano erupt on Iceland at all? Why are there volcanoes underlying structure of the earth. The answer lies in the on the Mid-Atlantic Ridge - Iceland sits a line of underwater volcanoes of the Atlantic Ocean. which runs the length two of earth's giant tectonic plates. The ridge marks the boundary between

These move slowly round the earth's surface, driven by heat currents deep within the planet. The plates either side of the Mid-Atlantic Ridge are moving apart as molten rock, or magma, rises up between them, forming underwater volcanoes. And there is another force at work. A hot spot - a narrow plume of heat hundreds or even thousands of miles deep. The combination of the Mid-Atlantic Ridge and the hot spot created enough volcanoes to push Iceland above sea level. Huge cracks running for miles across the landscape show that Iceland itself is slowly being split as the plates below it move apart.' So we're flying right between the two plates now. Um...and as the oceanic crust on either side pulls apart, magma rises up from the mantle along fissures. A lot of the volcanoes in Iceland are lined up with that rifting zone. 'With an average of one eruption every five years, Iceland is one of the most volcanic places on earth. A team of scientists monitor Iceland's volcanoes, so while this eruption took most of the world by surprise, geologists knew it was coming.' MAN: We're actually very good at predicting some aspects of volcanic eruptions, because magma can't get from deep down to the surface without breaking rock, and we can see that because we can pick up that breaking on seismometers. So we generates small earthquakes. Also, magma has to make space for itself, so it swells the crust, and we can detect that using things like the global positioning system. 'The first signs that the volcano might be waking up came five months before it blew.' So the story of the eruption begins back in December 2009, when Icelandic geologists first started to pick up tremors beneath the earth. These are hundreds of thousands of tiny earthquakes taking place deeper down beneath the volcano. Not the kind of big earthquakes that we read about and saw about

that destroyed Port-au-Prince in Haiti. These are much smaller - magnitude 1, magnitude 2 earthquakes. But what they tell geologists is that something's happening. There's some movement or motion of fluids - in this case magmas - at depth. 'Satellite measurements revealed that the volcano was beginning to deform alarmingly.' And sometime round about the end of February, the GPS monitoring registered quite big shifts - several centimetres or so - in the slope or the tilt of the volcano. And those two things together - the earthquakes and the inflation or the tilting of the slopes of the mountain - tell us that something's going on inside the volcano. 'On 20 March, the volcano erupted... ..and Icelandic television captured the first remarkable images. But the rest of the world took little interest.

The volcano erupted on its bare flank. There was nothing to stop the lava flowing freely out of the fissure. The eruption continued for three weeks and then abruptly stopped. But the Icelandic geologists monitoring the volcano knew there was more to come.' The magma flow into the volcano did not stop, so it was just the outflow channel that was clogged. So the volcano was ready to erupt again. 'But where would it erupt? There were worrying signs that the magma was building up beneath the main crater. There hadn't been an eruption here since 1821 and the crater was buried beneath seven hundred feet of glacial ice.' So it's a pressure cooker, and you heat it up to the point where you blow the lid off the thing, and the lid in this case is the ice cap on top. 'On 14 April, the volcano erupted again. This time, the dramatic pictures caught the world's attention. The new eruption broke out five miles away from the original fissure. The eruption site was in the volcano's main crater, deep under the ice cap. As the rising magma was forced up into the ice above, it was instantly chilled. The contact of super-hot and icy cold blew the magma apart with explosive force, pulverising it into billions of minute particles. The volcano blasted its way through the ice cap, hurling out these particles as clouds of volcanic ash. And there was something else. The chemical composition of the magma had changed from the first eruption. It was much stickier, and that made it much more explosive.' Explosive eruptions are driven by gas in the magma, so as the magma rises towards the surface and it reaches the very low pressures of the atmosphere, gas bubbles in the magma form and expand, and they tear the magma apart and they blast it upwards. 'Driven by the energy of the volcano, the cloud of fine ash was hurled five miles into the atmosphere. Nick Petford has left the main crater and is now heading for the site of the first eruption.' This is a small volcano.'s on the flank of the larger one. It's steaming... You can see the steam down there. Uh...looks like it's still hot. I'm gonna go down there and find a safe place to land and see if we can look at a bit of the rock. look at it. This is volcanic ash. This is what happens when you mix volcanic ash with meltwater from snow and ice. It forms this gloopy thick paste that just covers the landscape. Um... It's not easy to walk on. It's incredibly slippery. Incredibly mucky. But this is the kind of material... the consistency of this material is what flushes down the rivers and into the sea, and this stuff here plasters on the edge of the coastline and sort of builds out new land into the sea, so in a funny way, we're looking at the creation of new land area in this gloopy material. Horrible. 'Only days earlier, this area was covered in lava and molten rock rained down from lava fountains hundreds of feet high.' This stuff's a couple of weeks old. Um...but there's no snow in this part, so we're a bit reluctant to go much further because I know that under this crust of rock there could still be hot magma - 400, 500 degrees Centigrade... well, hot rock, anyway - so I don't really wanna fall through. And all around you can see evidence of geothermal activity still. There's the smouldering fumaroles. The snowline stops halfway up the hill there, which tells me that it's hot and I'm not really willing to walk any further. So this kind of lava is called basalt, and it erupts all over Iceland. In fact, Iceland is built...constructed out of the ocean on this material. Now, it's covered in this layer of dust. This is the sort of fine ash that gets blown out of the volcano in the early stages of the eruption. So this basalt rock all around me is full of holes, and these tiny holes are where the gas that came up with the magma from inside the earth escaped to the atmosphere and trapped in, if you like, fossil bubbles. And that's what these holes represent. So this tells me straightaway that the magma that came out here was gas-rich. And the reason that this lava flow wasn't particularly dramatic in terms of it being explosive was because it's runny enough - and that means it's got a low enough viscosity - that the gas can escape easily from the magma, and that's an absolutely key point which helps explain why some volcanoes blow up in a violent fashion and others just form lava, which vents relatively more passively down the volcano and flows down the slopes. 'Suddenly, Petford is called back to the helicopter. The wind has changed direction and ash is raining down. It's a stark reminder that this is still a dangerous place to be.' We've been lucky in the sense that this is a small eruption. There are eruptions that have happened in the past that are thousands of times bigger than this. The big problem is that it's producing, or has produced ash, which just happens to have headed in our direction. 'But what was it about this ash cloud that brought air traffic over Europe to a grinding halt? When a volcano in Iceland exploded beneath its ice cap in April 2010, the repercussions quickly spread across the world.

British geologist Nick Petford was exploring the eruption zone on the ground... ..while the danger was rising skyward. The volcanic ash cloud drifted five miles above Iceland, where it met a strong wind blowing from the north-west. The ash was caught in a jet stream... ..a fast-flowing high-altitude air current that circles the Northern Hemisphere. Up here, above 27,000 feet, the ash was stuck at the same height that jetliners fly. It meant the cloud of volcanic particles was blown to the south-east towards Britain and the rest of Europe.

In Britain, the Volcanic Ash Advisory Centre, a branch of the Met Office, used a computer model to calculate where and when the ash cloud would enter British air space. An urgent alert was sent to the National Air Traffic Service, NATS, who control Britain's commercial air space. They had to act quickly.' It is actually fairly black-and-white. If there is a known flight hazard, and the volcanic ash cloud constituted a known flight hazard, then we are required to restrict air space. 'All commercial air corridors were closed. Britain was paralysed.' There's obviously no flight for us at the moment. The airport is closed. 'The flight ban spread across Europe. Within four days of the eruption, nearly all of Europe's major airports were closed. For the first time ever, a natural event had closed a continent. The consequences soon became obvious. Thousands of holiday-makers were stranded abroad.' I'm a schoolteacher. I should have been back at school yesterday. They told me there were no flights at the airport, so they sent us here, but now there are no trains. 'British airports were empty and the missing tourists cost the country millions of pounds. Fresh produce, normally flown in, was running out. Medical supplies and organ donors couldn't be flown to where they were needed. As the flight ban continued, specially equipped plans were sent to check just how much ash was floating across British air space.' MAN: Speaking as an aeronautical engineer, I wouldn't want to be putting a big aeroplane up there at the moment. There's a lot of fairly nasty stuff there that certainly we were running away from. 'The threat was being monitored by meteorologists up and down the country.' We learnt about it on the Thursday morning, the same as everyone else did. As we were on our way to work we certainly heard the air space was being closed. 'To measure the height and size of the ash, the team at the University of Reading used LIDAR. It works like radar, but uses laser light instead of radio waves. Pulses are fired straight up into the atmosphere.

Anything they hit bounces light back and is picked up by the sensor.' The advantage of the laser, of course, is you send the pulse up, it comes back and the time tells you how far it is, so you know whether it's at 3,000 feet or 10,000 or 20,000 feet. from other dust, 'The LIDAR separates the ash giving a picture of the sky above.' in the atmosphere, MAN: The normal dust you get the lowest kilometre or so - which is normally confined to have seen this and I think most people with an aircraft... when you come in to land kilometre, it gets rather hazy. You suddenly, in the lowest they're spherical, And the dust particles, and they're this blue colour. But look at this on this trace here. It's got this red colour, these particular particles, and that's telling us that far from being spheres, are like shards. from the ash and very sharp, Like little shards of glass and this was the difference here. So this is really rather unusual to see. In fact, we haven't seen echoes like that before in this part of the world. 'To collect even more precise data, the team released sensors into the sky using helium balloons.' So this is the instrument package. We've got an inlet here. There's a pump inside this box, and within the box there's a laser beam, we can detect individual particles, and as the particles go past, then work out what their size is, there are. and work out how many of them Three, two, one, go. the LIDAR results. 'The airborne sensors confirms Floating up to 27,000 feet was a layer of volcanic ash. Their measurements also revealed so far south. why the particles had travelled They were extremely small and light.' was only about one micron. The size of the particles Now, normally, from volcanoes, the particles are much bigger - 20, 30 microns - the volcano which means they come out of the atmosphere. and then they fall out of about this So what was so unprecedented once it was up in the air, was that that meant injected up to 5, 10 kilometres, and didn't fall out. it just stayed there were the result 'The tiny ash particles of the eruption, of the explosive nature struck the glacier above. when gas-laden magma

Back in Iceland, is downwind of the eruption zone. geologist Nick Petford in the same volcanic ash The area is carpeted that brought Europe to a standstill.' What it does here to the local farms and covers absolutely everything. is that it falls as a blanket Um...and you can see all around me have just been matted the way that the fields layer of ash. in this couple of inches thick And it's rained recently, and when the ash that is wet, it develops a crust. when it starts to dry And it's quite hard sometimes through that crust, for the crops to penetrate so it prevents crop growth. it blocks out sunlight. Also, of course, of damage - catastrophic damage - So, all in all, it does an awful lot to the local farms around here. it's about a centimetre thick - So this is a layer of ash - to the volcanic vent. which fell quite close the very fined-grained material But it's pretty much similar to over Europe. that's now up in the atmosphere a bit closer by. This just happened to land just scraping the surface And you can see what I'm doing here, is coming off my hands. and all this fine powder It really is just like flour. in the atmosphere for a long time. You can see why it remains up the hazard for aircraft.' 'This fine-grain ash is what creates a whole number of problems Volcanic ash causes to the operation of aircraft. in front of a sandblaster. Imagine parking your airplane of the windshield. You have immediate pitting it's very hard to see out of. Basically, it becomes opaque and with the ash itself You also have all kinds of problems the navigation equipment. mixing with the avionics, the flight surfaces, the wings. It begins to erode The biggest problem that we have is into the large jet engines, as that ash is ingested passenger aircraft - particularly on wide-bodied jets - it melts the ash and can cause engine failure. 'Over the past 30 years, there have been more than 100 recorded cases in which volcanic ash has caused aircraft damage. The most famous was in June 1982. BA flight 9 was en route to New Zealand. After a stop-off in Kuala Lumpur, the captain noticed something strange.' We were watching a display on the windscreens

it's the static discharge Now, that's... that occurs around an aeroplane and it manifests itself up and down the windscreen. as shimmering light had flown into an ash cloud 'Without knowing it, Captain Moody Mount Galunggung. thrown up by the Indonesian volcano, produced the St Elmo's fire effect. Charged particles of fine ash had a more frightening turn.' But soon events took whatsoever. There was nothing on the radar "No. 4 engine's failed." And then the flight engineer said, to be shut down. So I called for that wasn't finished, though. The flight engineer gone and we've lost the lot." He then said, "No. 2's gone, no. 3's So there we were, up at 37,000 feet, Indian Ocean, out over the south-eastern and heaviest glider. with the world's largest 'Captain Moody's only hope was to descend to cleaner air, where he might be able to restart the engines. After dropping 20,000 feet, he put fuel back into the stalled engines and started the ignition sequence.' Where it wasn't igniting in the engines, of the tail cone it was coming out the back and igniting in the atmosphere, we had four engines on fire so it looked as though with the flames coming out the back. of the aircraft If you were down the back that that wasn't normal. you certainly knew lay in Captain Moody's hands. 'The lives of nearly 250 people Finally, after 50 attempts, an engine started. from impact in the sea, Just ten minutes away all four engines. they managed to restart the plane towards Jakarta Captain Moody and his crew steered to make an emergency landing.' the end of the runway At about 100 feet over I slid back in the seat and said, We're safe and sound now." "Right, that's it, lads. kissed the earth. It was wonderful. And the aeroplane, as good as gold, 'This near disaster is a reminder of how vulnerable aircraft are to volcanic ash. Professor Riti Singh is an international authority on aircraft jet engines.' I think it's understandable that when people look at large aircraft and the fact that they fly all over the world, one's experience it seems somehow outside could damage the whole engine. that small particles of ash

clean air and compressing it. 'A jet engine works by sucking in Then, in a combustion chamber, 1,500 degrees Celsius - the air is heated to around hotter than the melting point of ash. The hot gases drive a set of turbines at the rear of the engine, before they're ejected pushing the plane forward.' through a volcanic dust cloud, When these engines are flying not because it's ash or dust, the problem arises compressor or even the turbine because if this went through the it would do very little damage. which is silica, What happens is that this ash, inside the combustion chamber melts. molten glass, Now we've got, effectively, the turbine blade and when it impacts this melted ash deposits, and it's like creating a sort of blockage. 'The build-up of glass starts to choke the flow of the hot gas through the turbine. The compressor becomes overloaded and the engine cuts out. This is one of the turbine blades from BA 9's 1982 flight. It shows the build-up of the glassy deposit the air flow through the turbine which partially blocked and caused the engine to cut out. The volcanic eruption in Iceland may not have led to any disasters in the air, but Iceland's past history has shown us that volcanoes can do much worse than disrupt air travel. They can endanger the entire planet. While the world's attention was focused on the ash cloud over Europe, the eruption caused another major problem in Iceland itself - flooding. As the volcano erupted through the glacier above it, the intense heat melted vast amounts of ice. Some of this meltwater turned to steam and exploded up into the ash cloud. But where did the rest go?' All the water will flood out the side of the volcano and down the side of the mountain, and these are huge floods. These floods in Iceland had Mississippi-scale flows, and, in extreme cases, Amazon-scale flows. 'Geologist Nick Petford arrives at the foot of the volcano just as a new pulse of floodwater cascades off the mountain.' So if you look behind me now you can see something absolutely spectacular - a new rush of floodwaters come down from the volcano, so clearly activity is increasing and it's started to melt more ice. Not all of it's gone. And if we were stood here when the eruption was taking place in a full flood, all this area would have been full of that material flooding down towards the sea, bringing great big blocks of ice the size of houses. It's really quite spectacular. 'Further down the valley, broken roads and huge blocks of ice scattered across the ground are graphic evidence that the floods in the first days of the eruption filled the whole of this landscape.' Two or three days ago, this whole area was... We would be underwater now. In fact, we'd have been washed away in seconds. The torrential force of the water coming down from the volcano as it melts was immense. It's like the cumulative effect of all the world's rivers put in one place, flowing for a brief moment in time. It might take two or three hours for water to get down from the mountains to the sea, but in that short amount of time the devastation is catastrophic. 'With regular volcanic eruptions every few years, Icelanders are used to this kind of natural hazard. It comes from living on a land that's still in the throes of creation. 25 miles north of the current eruption is Iceland's most active volcano. Today, it's called Hekla. In the Middle Ages, it was known as the gateway to hell. It's a 3.5-mile-long fissure that's erupted more than 20 times in the last thousand years...

..the last time only ten years ago. None of Iceland's rocks is more than 15 million years old. Mere youngsters in geological time. And the youngest addition to the country of Iceland was born less than 50 years ago. The island of Surtsey emerged spectacularly from the ocean

in November 1963. The crew of a trawler sailing off the south-east coast of Iceland spotted a column of smoke rising from the sea. A volcano had begun erupting on the ocean floor. Within days, the eruption reached the surface and a new island began to form. After two weeks, the island was half a mile long. Although the sea quickly washed away the loose ash that accumulated on the shores, solid lava built up and Surtsey steadily grew. The eruption continued intermittently for the next 3.5 years, creating a new part of Iceland. Surtsey is a miniature example of how Iceland itself must have formed, growing from a tiny island emerging from the Atlantic Ocean to a land mass of 40,000 square miles. But Iceland hasn't finished forming yet. Icelanders know they must be ready for the next violent eruption and that sometimes their homes and their lives may be at risk.

This is the island of Heimaey, just 11 miles from Surtsey and right on the Mid-Atlantic Ridge. It's home to about 5,000 people. In January 1973, a volcano erupted without any warning only half a mile from the centre of the main town. Within hours, lava was fountaining up to 500 feet high

from a fissure two miles long, which split the island from one shore to the other. Heimaey's inhabitants were hurriedly evacuated as the volcano devastated their town. In a few days, the lava and the constant rain of black ash had destroyed and buried hundreds of homes.

Then, one lava flow changed direction and threatened to block the harbour entrance - a lifeline for this fishing community. The local people decided to challenge the volcano. They couldn't stop the lava flow, so they came up with an ambitious plan to divert it. They brought in huge water pumps and for several weeks sprayed the edge of the lava with millions of gallons of sea water. Incredibly, it worked. The lava solidified into a wall, which diverted the main flow safely away from the harbour. The town and its livelihood were saved.' The harbour is now sheltered by the new lava instead of being filled by it, and the harbour is still there. In fact, it's a much better harbour than it was before the eruption. 'By Icelandic standards, Heimaey was a tiny volcano. But back in Iceland's past there have been huge eruptions which caused devastation around the world. In England, the summer of 1783 was known as the sand-summer. For weeks, a mysterious ash fell out of the sky, turning the sun red and filling the air with a smoky haze. And this was the cause. This is Laki, in southern Iceland, a line of craters and lava flows which mark the world's most destructive volcanic eruption in recorded history. In June 1783, a 16-mile-long fissure ripped Iceland apart. Lava poured out of 130 craters. Eyewitnesses at the time estimated that lava fountains soared up to more than 4,000 feet high as billions of tonnes of lava were erupted over the next eight months.

But it wasn't lava that made the Laki eruptions so dangerous. It was the enormous clouds of ash and gas. The 1783 eruptions made the recent Eyjafjallajokull volcano seem puny. The fissure disgorged 120 million tonnes of sulfur dioxide, along with eight million tonnes of lethally corrosive hydrogen fluoride. The cloud of ash and gas blanketed Iceland. The consequences for humans, animals and crops were catastrophic. A quarter of the population died, either by starvation or fluoride poisoning. 80% of the sheep and half the cattle and horses perished. The cloud spread out to Europe and beyond.' And that caused stifling, poor quality air in the summer. It raised mortality rates maybe by 10 or 15% in some places. And then in the following winter it caused much, much lower temperatures. 'More than 30,000 people in England were estimated to have died from poisoning and starvation. Over the next two years, the fallout caused famines all over Europe and as far afield as Asia. The Laki eruption may have even contributed to the French Revolution in 1789, which was partly triggered by years of famine and poverty.' So we're used to the idea that events in Iceland can affect us in the UK and in Europe, so it really shouldn't have been a surprise this time. 'As Europe begins to count the cost of the recent Eyjafjallajokull volcano, the question is could a Laki-style eruption happen again and when? And how much disruption would it bring? In April 2010, the world was shaken by the effects of the eruption of an Icelandic volcano.

While British geologist Nick Petford flew above the eruption's ground zero...' It's absolutely fantastic. Just spectacular. '..aircraft all over Europe were grounded. Fearing jet engines would be crippled by contact with the volcanic ash cloud, 100,000 flights were cancelled in the biggest shutdown of air space since the Second World War. Chaos reigned.' I've got no money left. I don't know where to go, what to do. I'm on my own, so... We lost our jobs when we don't come to the work. It's an absolute nightmare. 'Suddenly, volcanic ash was top of everyone's agenda. After six days of unprecedented negotiation between engine manufacturers, airlines and governments, new safety rules were announced.' The Civil Aviation Authority of Britain have now reached decisions about the tolerance levels which are safe for planes to fly in areas where ash is present. 'They decided that any ash cloud with less than two milligrams of particles per cubic metre would not damage the turbine blades of jet engines. Tests showed that the ash cloud over Britain had by this time had dispersed to below this critical level. It was no longer seen as a threat. The skies were open again.' The previous rules were avoid, avoid, avoid. Any ash, keep away. Of course, we've learnt a lot from this situation here, and now the level of ash which causes difficulty in engines has been much better defined. 'Air travel across Europe slowly returned to normal. But the world woke up to the damage volcanoes can inflict on our modern global society. And we have every reason to be wary. There may be worse to come.' This eruption in Iceland is really quite small. On a scale of things, it's nowhere. Much bigger eruptions have happened in the past in Iceland and much bigger eruptions will happen in the future. 'Future eruptions could cost us more than our flights. They could cost us our way of life.

The gigantic 1783 Laki eruption should act as a warning that clouds of volcanic ash and gas could do a lot more than close our air space. They could change our climate, lowering temperatures and devastating crops. Just 20 years ago, the entire planet had a timely reminder of what a volcano can do.' In 1991 there was a very large eruption of a volcano called Mount Pinatubo, which is located on central Luzon, in the Philippine islands. There was about five cubic kilometres of magma that was erupted during that particular event. 'A cloud of ash and 20 million tonnes of sulfur dioxide gas exploded out of the mountain.' In some areas immediately surrounding the volcano, we developed what's called an ash flow sheet, which is hundreds of metres, potentially, in some areas, thick of volcanic deposits. 'Locally, it was a human tragedy. But the effects were felt globally. Huge quantities of ash and gas forced high into the atmosphere formed a planet-wide blanket, filtering out sunlight. As a direct result, between 1991 and 1993, average global temperatures dropped by half a degree. Climate-cooling eruptions like Pinatubo are rare. Fortunately, eruptions on the scale of Laki in Iceland But if we continue to warm up our planet, this could change. Strangely, global warming may increase the chances of huge eruptions, producing gas clouds that actually cool the planet. Since the peak of the last ice age 20,000 years ago, our planet has been heating up. And as it's warmed, new volcanic threats have emerged.' If we look back in time at periods of dramatic climate change, particularly when we came out of the last ice age, we see that it coincides with increased volcanic activity. So looking ahead, we might expect to see a volcanic response to anthropogenic climate change - the climate change caused by human activities. 'The reason for this correlation is that global warming can melt the planet's ice sheets. If they melt in Iceland, dormant volcanoes buried under ice for thousands of years may become active. The process is called "unloading".' During the last ice age, Iceland was completely covered with a very thick carapace of ice, and at that time, volcanic activity was suppressed because of the load of ice sitting on top of these volcanoes. So the pressure was sort of bottling in the gases and they weren't able to explosively come out and generate an eruption. Now, we still have a little bit of Iceland left which is an ice sheet - the Vatnajokull ice sheet - and there are many other volcanoes there as well. If that Vatnajokull ice sheet is melted, which it will do if we have unmitigated emissions and carry on warming the planet, then these volcanoes will be encouraged to erupt in the same sort of way. 'Global warming may mean that the volcanic threat from Iceland will grow. And although we can't stop future eruptions, we can be more prepared.' Volcano monitoring and our ability to forecast hazardous volcanic eruptive activity has come a long way. With proper advance planning and long-term monitoring programmes, many of these events can be forecast. We're getting quite good at saying, "This volcano's going to erupt next Wednesday." That helps - it helps in terms of disaster management

and emergency management, evacuation, et cetera, but it doesn't tell us anything about how big the eruption's gonna be or how long it's gonna last or when the really big bang's gonna happen. Um...and that's the problem. 'In Iceland, geologists are vigilant, looking for any sign of eruptions. And they now believe there is a new threat. Less than 20 miles from the smouldering peak of Eyjafjallajokull lies its hidden neighbour, Mount Katla.' All of this in front of me now is ice - it's a glacier - but underneath it, same dimensions, is a volcano called Katla. When it erupted in 1918 it was one of the most powerful eruptions of the 20th century. 'Katla emits ten times as much material as its sister volcano. Patterns of historic eruptions have led scientists to believe the two volcanoes are connected. The last three times Eyjafjallajokull has erupted, Katla was quick to follow.' As far as we can tell, the magma is not fed from the same batch beneath the two volcanoes, but it seems that Eyjafjallajokull, by erupting, it sort of sends off some kind of vibrations or maybe, yeah, pushes Katla to erupt as well. 'But detecting early signs of activity beneath thousands of feet of ice is difficult.' One of the first things we would see if hot magma was rising up there would be some disturbance of the ice layer above it. Now, flying over the volcano there's no obvious signs, looking down, of cracks, but what we do see here are these hollows and depressions. Now, these may be the sites of the 1918 eruption or they may be ground subsidence where the volcano's starting, very gently, to warm up. 'So far, Katla has remained silent.' MAN: We are monitoring Katla very thoroughly. So far, we don't see any signals from Katla that it might be about to erupt. But Katla is a very active volcano. It's a rather fierce volcano. But if my feet were perhaps 300 to 800 metres down, there's a 10-kilometre-wide crater. Katla hasn't exploded yet, but it's just a matter of time before this one does go up. We know it's overdue. It could happen any moment. 'The results of a Katla eruption would be disastrous. Within a few hours of the 1918 eruption, Katla had vaporised its overhead glacier, discharging nearly 18 million tonnes of meltwater every minute onto the plains below. It was more than ten times the average flow of the Nile and Mississippi rivers combined and caused immense devastation. Fearing a repeat of this calamity, the Icelanders are preparing for the worst and also sending us a warning.' What we have seen now is, in fact, a small rehearsal of what would happen. I...I don't say if, but I say when Katla will erupt, for European governments so I think it is high time all over Europe and the world and airline authorities the eventual Katla eruption. to start planning for another much larger ash cloud 'A Katla eruption means we could see heading our way sometime soon. our air space Once again, ash would threaten and disrupt our travel. of the island's history And, from what we know over the last few hundred years, this won't be the last we'll have to face. or the most destructive eruption how big the next eruption will be. We don't know for sure when, where or

hasn't finished with us yet.' What we do know is that Iceland Closed Captions by CSI *